As is well known in the art, internal combustion engines produce mechanical power from the chemical energy stored in hydrocarbon fuel. This energy is released by oxidising or burning fuel within the cylinders of the engine.
The amount of power released from the fuel is function of the degree of oxidation and, hence, is dependent on the amount of oxygen available during combustion. As a general principle, the greater the degree of oxidation of the fuel, the higher the efficiency and the greater the power output, reflected respectively by the gas mileage and horsepower of a vehicle.
Three major pollutants typically result from combustion of hydrocarbon in internal combustion engines. These pollutants are oxides of nitrogen, oxides of carbon and hydrocarbon. Carbon dioxide is generally considered a non-toxic necessary by-product of the hydrocarbon oxidation process.
With respect to the nitrogen oxide emissions, their formation is understood to be largely a function of combustion temperatures. However, it is presently understood that leaner fuel-air mixtures and improved mixing of fuel and air may tend to reduce the formation of nitrogen oxides.
With respect to carbon monoxide and hydrocarbon emissions, it is understood that increased oxidation during combustion tends to reduce the formation of these compounds by way of oxidation.
A conventional method for reducing emissions to the environment of the by-products of internal combustion engines oxidation is to use so-called catalytic converters. Catalytic converters however suffer from numerous drawbacks. For example, they are relatively costly and their effectiveness is reduced over time. Hence, they require periodical inspection and replacement to maintain performance.
The life-span of conventional catalytic converters is understood to be a function of the amount of pollutants (primarily unburned hydrocarbons) the device has processed. Accordingly, in addition to increasing the efficiency and power output of combustion, increasing oxidation during combustion is also likely to increase the life-span of the conventional catalytic converters.
As is also well known in the art, reciprocating engines of the Wankel-type typically include a piston mounted for reciprocating or back and forth movement in a cylinder. The piston transmits power through a connecting rod and crank mechanism to the drive shaft. The majority of reciprocating engines operate on what is called a four-stroke cycle, i.e. each cylinder of the engine requires four-strokes of its piston or two revolutions of the crank shaft to complete the sequence of the cycle which produces one power stroke.
The first stroke is termed an intake stroke. It starts with the piston at the top centre crank position and ends with the piston at the bottom centre crank position. As the piston moves from the top to the bottom centre crank position, fresh intake mixture generally comprised of air or air and fuel is drawn into the cylinder through an inlet valve. The inlet valve typically opens just before the stroke starts and closes shortly after it ends.
Whether the intake mixture drawn into the cylinder is comprised of air or an air and fuel mixture is dependent on the engine. For example, in a typical spark emission engine, air passes through an air filter and then is mixed with fuel in the intake system prior to entry to the engine using a carburetor or fuel injection system. The air-fuel mixture is then drawn into the cylinder via the intake valve during the intake stroke. In comparison, a compression ignition engine inducts air alone into the cylinder during the intake stroke and the fuel is directly injected into the engine cylinder just before combustion.
Within internal combustion engines found on most vehicles, the engine takes in large volumes of air at a relatively rapid rate which is then conducted to Venturis within a carburetor is to be mixed with vaporised gasoline and then conducted within the firing cylinders of the engine.
At present, carburetors manage to vaporise approximately 40% of the gasoline in the air and this slow vaporisation rate results in incomplete and inefficient combustion of the gasoline in the engine cylinders, resulting in relatively poor gasoline mileage for the vehicle being driven and relatively high output of combustion products or pollutants.
The use of means for improving the degree of oxidation of the fuel in an internal combustion engine has long been known. For example, in order to increase the volume of the intake mixture into the combustion chamber of internal combustion engines, devices such as turbo-chargers and super-chargers are sometimes used. Although somewhat useful, such devices suffer from numerous drawbacks including that they are relatively expensive to manufacture and service. Furthermore, they draw usable power from the engine and are prone to wear. Still furthermore, they require space within the engine compartment for mounting and increase the overall weight of the motor vehicle.
Another type of means used for improving the degree of oxidation of the fuel in an internal combustion engine includes positioning a structure within the fuel/air stream prior to entry within the firing cylinders so as to cause turbulence of the fuel/air stream. The use of such structures allows the air entering into the combustion chamber to be in a swirling or turbulence state. Turbulent air flow provides a more complete and uniform mixture of air/fuel and, hence, improves the combustion of the charge within the combustion chamber.
The prior art has shown some examples of air turbulence generators for internal combustion engines. For example, U.S. Pat. No. 6,158,412 issued to Kelsen and naming J. S. Kim as inventor discloses a device which may be used to create swirling, turbulent flow to the air entering an internal combustion engine and to the exhaust gases therefrom prior to the gases entering an air pollution system.
The device utilises multiple curved and radially angled vanes to force the air into a predetermined turbulent, swirling pattern. For carburator engines, the device is positioned between the air filter and the inlet to the carburettor and on fuel injection engines, the device is positioned at the inlet port of the intake manifold. Within the exhaust system, the device is positioned within the exhaust tubes just upstream of the catalytic converter to force the gases into a swirling and turbulent flow.
U.S. Pat. No. 6,041,753 issued Mar. 28, 2000 to Lyn et al. discloses an intake swirl enhancing structure including a guide shaft and several guide interfaces radially extending from the guide shaft to split a space into several intake passages. Each of the guide interfaces has a curved outer corner near an outlet end of the intake passages to swirl gas flowing through and out each intake passage.
Although somewhat useful, known prior art gas swirling devices suffer from numerous drawbacks. For example, the flow pattern created by prior art gas swirling devices is often considered to be sub-optimal. Also, the proportion of the surface of the guiding vanes being used for effectively guiding the flow of gas is often considered to be too small.
Furthermore, some prior art devices suffer from the particular defect of overcomplexity, with resulting high manufacturing costs and a propensity to require service and/or repair. Some prior art devices also create an undue restriction to the flow of gases.
Accordingly, there exists a need for an improved flow guiding structure. It is a general object of the present invention to provide such an improved flow guiding structure for internal combustion engines.
In accordance with an embodiment of the present invention, there is provided a flow guiding structure for guiding into a predetermined flow pattern a flow of gas flowing into a gas passageway leading towards a combustion chamber of an internal combustion engine, the gas passageway including a passageway delimiting wall and defining a passageway axis, the structure comprising: a substantially tubular peripheral wall delimiting a structure passage, the peripheral wall defining a peripheral wall first edge, an opposed peripheral wall second edge and a passage longitudinal axis; the peripheral wall having a base section extending from the peripheral wall first edge for allowing the structure to be secured to the gas passageway; the peripheral wall also having a guiding section extending substantially from the base section to the peripheral wall second edge for allowing the flow of gas to be guided into the predetermined flow pattern; a plurality of guiding vanes, each extending substantially radially inward from the guiding section about a corresponding vane first edge; each of the vane first edges extending from a first edge proximal end located substantially adjacent the base section to a first edge distal end located substantially adjacent the peripheral wall second edge; at least one of the guiding vanes including a vane second edge extending in a second edge geometrical plane substantially perpendicular to the structure longitudinal axis from the first edge distal end to a second edge distal end; the at least one of the guiding vanes also including a vane third edge extending from the second edge distal end to the first edge proximal end.
In accordance with an embodiment of the present invention, there is also provided flow guiding structure for guiding into a predetermined flow pattern a flow of gas flowing into a gas passageway leading towards a combustion chamber of an internal combustion engine, the gas passageway including a passageway delimiting wall and defining a passageway axis, the structure comprising: a plurality of guiding vanes, each extending substantially radially inward from the guiding section about a corresponding vane first edge; each of the vane first edges extending from a first edge proximal end located substantially adjacent the base section to a first edge distal end located substantially adjacent the peripheral wall second edge; each of the guiding vanes including a vane second edge extending in a second edge geometrical plane substantially perpendicular to the structure longitudinal axis from the first edge distal end to a second edge distal end; each of the guiding vanes also including a vane third edge extending from the second edge distal end to the first edge proximal end.
In accordance with an embodiment of the present invention, there is further provided a flow guiding structure for guiding into a predetermined flow pattern a flow of gas flowing into a gas passageway leading towards a combustion chamber of an internal combustion engine, the gas passageway including a passageway delimiting wall and defining a passageway axis, the structure comprising: a substantially tubular peripheral wall delimiting a structure passage, the peripheral wall defining a peripheral wall first edge, an opposed peripheral wall second edge and a passage longitudinal axis; the peripheral wall having a base section extending from the peripheral wall first edge for allowing the structure to be secured to the gas passageway; the peripheral wall also having a guiding section extending substantially from the base section to the peripheral wall second edge for allowing the flow of gas to be guided into the predetermined flow pattern; a plurality of guiding vanes, each extending radially inward from the guiding section, the guiding vanes being configured, sized and positioned so as to guide the flow of gas into the predetermined flow pattern; the guiding section being provided with at least one guiding bent formed therein and extending substantially inward into the structure passage, the at least one guiding bent being configured, positioned and sized so as to act as an auxiliary guide and cooperate with the guiding vanes for guiding the flow of gas into the predetermined flow pattern.
In accordance with an embodiment of the present invention, there is still further provided a flow guiding structure for guiding into a predetermined flow pattern a flow of gas flowing into a gas passageway leading towards a combustion chamber of an internal combustion engine, the gas passageway including a passageway delimiting wall and defining a passageway axis, the structure comprising: a substantially tubular peripheral wall delimiting a structure passage, the peripheral wall defining a peripheral wall first edge, an opposed peripheral wall second edge and a passage longitudinal axis; the peripheral wall having a base section extending from the peripheral wall first edge for allowing the structure to be secured to the gas passageway; the peripheral wall also having a guiding section extending substantially from the base section to the peripheral wall second edge for allowing the flow of gas to be guided into the predetermined flow pattern; a plurality of guiding vanes, each extending substantially radially inward from the guiding section, the guiding vane being configured, sized and positioned so as to guide the flow of gas into a substantially clockwise swirling flow pattern.
Advantages of the present invention include that the proposed structure allows for a flow of gas flowing into a gas passageway leading towards the combustion chamber of an internal combustion engine to be guided into a predetermined flow pattern so as to improve the mixing of air and fuel in the combustion chamber.
The proposed structure allows for the guidance of the intake flow into an optimally configured intake swirl or vortex pattern. The swirl is directed in a clockwise direction and generally radially outwardly. The induction of such an airflow configuration has been found to improve gas mileage, increased horse-power as well as reduced carbon monoxide and hydrocarbon emissions.
It is presently understood that the reason for these results is increase air intake to the cylinder or improved mixing of the fuel and air prior to combustion which is understood to likely result in the improved oxidation of the fuel. It is also presently understood that the increased air intake is likely to be the result of similarities in geometry between the valve head and the swirling air flow or vortex. These similarities may likely result in the valve head opposing less resistance so the intake mixture.
The guiding vanes of the structure are configured, sized and positioned so as to optimize the proportion of the surfaces effectively guiding the flow of gas. Also, the proposed device is provided with auxiliary guiding means for further improving the guiding of the flow of gas. The auxiliary guiding means also act as a structural reinforcement for the proposed structure.
The proposed structure is designed so as to be usable with various types of fuels and various types of engines including naturally aspirated and turbo-charged positive displacement internal combustion engines using carburettors, fuel injection or the like. The proposed device is further designed so as to prevent undue flow restriction which could starve the engine of air and/or cause incomplete combustion and sluggishness.
The proposed device is designed so as to be mountable at various locations including in close proximity to the intake of the combustion engine through a set of quick and ergonomical steps without requiring special tooling, manual dexterity or major alterations to the conventional engine and/or its accessories. The proposed device is designed so as to be easily retro-fitted to existing engines as well as installed with new ones.
Typically, the proposed structure is designed so as to be manufacturable out of an integral piece of material through a set of bending and die-cutting operations. Yet, still furthermore, the proposed structure is designed so as to be manufacturable using conventional forms of manufacturing and conventional materials so as to provide a structure that will be economically feasible, long-lasting and relatively trouble-free in operation.
Optionally, the device allows for various types of swirl energy in the intake air based on characteristics of the engine and other vehicle parameters. For example, a general high swirling motion of the air is needed in the combustion chamber at lower engine operating speeds in order to enhance the fuel/air mixing process while a lower swirling motion of the air is desirable at higher engine speeds during which the swirl energy needed to assist in the mixing process is reduced due to the increased energy derived from the incoming gases at the higher piston speeds.